The study was aimed at assessing feasibility of treatment of patients suffering from critical ischaemia of lower extremities with iloprost as compared to the basic therapy by means of pharmacoeconomic analysis. The findings of clinical studies and meta-analyses demonstrated that therapy with iloprost results in a pronounced clinical effect as compared with the basic therapy: significantly (p<0.005) decreasing the number of amputations above the knee joint (23% versus 39%) and more frequently decreasing the size of trophic ulcers (in 49% of cases versus 26%). This provides maintenance of the ability to work in part of patients and a decrease in the frequency of hospitalization, which in its turn results in decreased costs of treatment and indirect expenses.. The results of the carried out study show that with due regard for only direct costs economy from treatment with iloprost would amount to 1,544,556 Roubles per 100 patients. With additionally taking into account of indirect costs economy from using iloprost as compared with basic therapy increases to 25,689,11 Roubles per 100 patients.